Saves a Tag and returns new ID. If the tag already exists, the existing Tag ID is returned. 

This method can be accessed through the Tags.asmx file located in:

~/Workarea/webservices/WebServiceAPI/Community/Tags.asmx

[SoapHeader("AuthHeader")]
[SoapHeader("RequestInfoHeader")]
[WebMethod(MessageName = "AddTag", Description = "Saves a Tag and returns new Id. If the tag already exists, the existing Tag Id is returned.")]
public long AddTag(ref TagData tag);

<SoapHeader("AuthHeader")>
<SoapHeader("RequestInfoHeader")>
<WebMethod(MessageName = "AddTag", Description = "Saves a Tag and returns new Id. If the tag already exists, the existing Tag Id is returned.")>
Public Function AddTag(ByRef tag As TagData) As long